A revision of Geonoma (Arecaceae)
Author
Henderson, Andrew
text
Phytotaxa
2011
2011-02-18
17
1
271
journal article
24911
10.11646/phytotaxa.17.1
65962ba7-eec1-40e7-aed6-cef94e99ca39
1179-3163
3538362
4.
Geonoma braunii
(Stauffer) Henderson
,
comb. & stat. nov.
Basionym:
Geonoma spinescens
var.
braunii
Stauffer (1997: 5)
. Type:
VENEZUELA
.
Yaracuy
: Mun. Nirgua, ca.
5 km
N of Nirgua, Cerro La Chapa,
10°12’N
,
68°33’W
,
1200–1300 m
,
28 November–1 December 1996
,
A. Fernández, F. Stauffer, R. Riina, K. Walter-Weissbeck & O. Kunert 10087
(
holotype
VEN
n.v.
).
Plants
2.0(1.5–2.5) m tall; stems 2.0(1.5–2.5) m tall, 1.0(0.8–1.2) cm in diameter, solitary or clustered, not cane-like or cane-like; internodes 1.0(0.3–2.1) cm long, yellowish and smooth.
Leaves
12(10–13) per stem, undivided or irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths
6.5 cm
long; petioles 13.9(8.0–22.0) cm long, drying green or yellowish; rachis 22.9(18.3–32.0) cm long, 2.1(1.4– 2.8) mm in diameter; veins not raised or slightly raised and triangular in cross-section adaxially; pinnae 2(1– 4) per side of rachis; basal pinna 24.9(17.5–33.0) cm long, 4.7(3.0–10.5) cm wide, forming an angle of 35(21– 53)° with the rachis; apical pinna 15.9(13.5–21.8) cm long, 10.3(6.5–17.8) cm wide, forming an angle of 24(18–28)° with the rachis.
Inflorescences
branched 2–3 orders; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers, flattened, deciduous; prophylls 5.3(4.5–6.1) cm long, short and asymmetrically apiculate, the margins curved around the stem, the surfaces flat with dense, felty, brown tomentum, prophyll equal to and early deciduous with the peduncular bract, the surfaces not ridged, without unequally wide ridges; peduncular bracts
5.8 cm
long, well-developed, inserted 0.2(0.1–0.4) cm above the prophyll; peduncles 10.6(6.0–14.5) cm long, 3.4(2.2–5.3) mm in diameter; rachillae 24(22–26), 7.0(6.0–8.5) cm long, 0.8(0.7–1.0) mm in diameter, the surfaces without spiky, fibrous projections or ridges, drying brown, with faint to pronounced, short, transverse ridges, filiform with extended narrowed sections between the flower pits; flower pits alternately arranged (sometimes distorted by twisting and contracting of rachillae), glabrous internally; proximal lips without a central notch before anthesis, not recurved after anthesis, not hood-shaped; proximal and distal lips drying the same color as the rachillae, joined to form a raised cupule, the margins not overlapping; distal lips well-developed; staminate and pistillate petals not emergent, not valvate throughout; staminate flowers deciduous after anthesis; stamens 6; thecae diverging at anthesis, inserted almost directly onto the filament apices, the connectives bifid but scarcely developed; anthers short and curled over at anthesis; non-fertilized pistillate flowers deciduous after anthesis; staminodial tubes crenulate or shallowly lobed at the apex, those of non-fertilized flowers not projecting and persistent after anthesis;
fruits
7.4(6.5–8.1) mm long, 6.0(5.1–6.9) mm in diameter, the bases without a prominent stipe, the apices not conical, the surfaces not splitting at maturity, without fibers emerging, bumpy from the numerous, subepidermal, tangential, short fibers present, these coming to a point at fruit apices; locular epidermis without operculum, smooth, without pores.
Distribution and habitat:—
From 10°09’–
10°15’N
and 68°28’–
68°37’W
in the Coastal Cordillera in
Venezuela
(
Yaracuy
), at 1192(
1045–1300
) m elevation in montane rainforest (
Fig. 10
).
Taxonomic notes:—
Stauffer (1997)
recognized this species as a variety of
Geonoma spinescens
. It is here recognized at the species level, differing from
G. spinescens
in its alternately arranged flower pits.
Subspecific variation:—
Three traits (stem branching, stem
type
, leaf division) vary within this species, but all specimens come from the same area.